How to place a div below a nested div?

How do I place a div below a nested div? Right now the third div (.box3) seems to overlap the second div when I want it to appear below the second div (.box2). Please see example: https://jsfiddle.net/662fwmq5/

<div class="box1">
Box 1
<div class="box2">
Fixed income, currency, and commodities revenue was $2.65 billion ($2.21 billion expected), up 39% thanks to stronger performance in credit products, especially mortgages, as well as in rates products and client financing. Equities revenue came in at
$954 million ($1.03 billion expected), down 17% because of lower client activity in cash and derivatives, which the firm said reflected lower market volatility.
</div>
</div>

<div class="box3">
More than 14,000 seasonal positions were transitioned to regular, full-time roles after the holidays last year, and the company expects to increase that number this year, Amazon said on Thursday.
</div>

My issue is further magnified when the screen size narrows. I want the third div (.box3) to respond to screen size changes so that the third div always appears below the second div (.box2).

<body>
<div class="box1">
Box 1
<div class="box2">
Fixed income, currency, and commodities revenue was $2.65 billion ($2.21 billion expected), up 39% thanks to stronger performance in credit products, especially mortgages, as well as in rates products and client financing.
Equities revenue came in at $954 million ($1.03 billion expected), down 17% because of lower client activity in cash and derivatives, which the firm said reflected lower market volatility.
</div>
</div>
<div class="box3">
More than 14,000 seasonal positions were transitioned to regular, full-time roles after the holidays last year, and the company expects to increase that number this year, Amazon said on Thursday.
</div>
</body>

If you can't change the height, you can overflow it using overflow-y: auto:

<body>
<div class="box1">
Box 1
<div class="box2">
Fixed income, currency, and commodities revenue was $2.65 billion ($2.21 billion expected), up 39% thanks to stronger performance in credit products, especially mortgages, as well as in rates products and client financing.
Equities revenue came in at $954 million ($1.03 billion expected), down 17% because of lower client activity in cash and derivatives, which the firm said reflected lower market volatility.
</div>
</div>
<div class="box3">
More than 14,000 seasonal positions were transitioned to regular, full-time roles after the holidays last year, and the company expects to increase that number this year, Amazon said on Thursday.
</div>
</body>